Question

a向量=（根号3cosx/2,2cosx/2）,向量b=（2cosx/2,-sinx/2）函数f（x）=向量a·向量b

Answer 1

(1)

f(x) = a.b

=（√3cosx/2,2cosx/2）.（2cosx/2,-sinx/2）

= 2√3(cosx/2)^2 - sinx

f（θ）=√3 +1

√3 +1 = 2√3(cosθ/2)^2 - sinθ

= √3( cosθ +1) - sinθ

1= √3cosθ - sinθ

1/2= (√3/2)cosθ - (1/2)sinθ

= sin(π/3+θ)

π/3+θ = π/6

θ = -π/6

(2) To be continued. .